Item Component Function
1 12Gbps SAS IN port (2) Provides host-to-controller SAS connection.
2 Seven segment display 
sequence 
Displays status or error codes for the storage array.
3 Controller power LED Lights green when controller power is on.
Turns off when controller is not powered.
4 Controller fault LED Lights amber when controller fault is detected.
Turns off when controller is operating normally
5 System identification LED Blinks blue when system identification switch push-
button on enclosure front panel is pressed.
6 Cache active or cache offload 
LED
Lights green when on-board controller memory 
contains data.
If AC power fails, this LED changes to indicate Cache 
offload status. If the password reset function has 
successfully changed the password, this LED flashes 
on and off briefly.
7 Battery fault Lights amber when battery backup unit or battery has 
failed.
Turns off when battery backup unit is operating 
normally
8 Management port Provides a 100/1000 Mbps Ethernet connection for 
out-of-band management of the enclosure.
9 Ethernet port (reserved) Reserved port.
10 12Gbps SAS IN port (2) Provides host-to-controller SAS connection.
11 USB port  Reserved port.
12 Mini USB port  Provides serial connection for debugging. 
13 Password reset switch Activating this switch resets the password.
14 SAS OUT Port (2) Provides SAS connection for cabling to a downchain 
expansion enclosure.
Using Port 0 is recommended.
RAID Controller Module—Additional Features
Battery Backup Unit
Each RAID controller contains a two-cell Lithium ion nanopolymer battery backup unit (BBU). It provides 
power to the RAID controller module in the event of a power outage. For information on removing and 
installing the BBU, see RAID Controller Module Backup Battery Unit .
NOTE: For virtual disks, the RAID controller firmware changes the data cache setting based on the 
state of the battery. If the battery is missing or does not have sufficient charge, the controller flushes 
the cache and sets the write cache attribute to Write Through for all virtual disks. When the battery 
is replaced, Write Back is re-enabled.
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